Joe Carr remembers exactly where he was when he found out that House Majority Leader Eric Cantor lost his race to the largely unknown political upstart David Brat.

As he finished up a meeting with a group of about 75 Tea Party supporters in Obion County, someone waved a smartphone and announced the startling news.

“The place went nuts… it exploded,” Carr said, pointing out that the event went long past 10:00 as supporters began discussing what was possible in his Republican primary challenge to Sen. Lamar Alexander.

“All of a sudden now the attention the attention turns to us; now it becomes ‘Yes we can.’ People were saying ‘Yes we can’ with hope; now we say ‘Yes we can’ with expectation, and it’s literally taken off since then,” he said.

Carr discussed his race with Breitbart News prior to Tuesday’s rally on his behalf with radio talk show host Laura Ingraham in Nashville.

As fate would have it, Carr already had a meeting with Ingraham scheduled in Washington, D.C., even before the Virginia surprise.

Ingraham, suddenly in the spotlight as a central figure for tackling Cantor’s support for immigration reform, indicated that she would be willing to support Carr’s unlikely challenge to Alexander.

It was certainly a bright moment for his campaign. And on Wednesday, Carr received the endorsement of former Alaska Gov. Sarah Palin, arguably the most significant endorsement a primary challenger could receive.

Alexander’s team, meanwhile, has dribbled out a series of endorsements from former star Republicans, including former Sen. Fred Thompson, Gov. Mike Huckabee, and Speaker Newt Gingrich.

“If anyone who wants to pick a fight with Lamar Alexander for supposedly not being conservative enough, well, you might want to pick a fight with me first,” Huckabee declares in one of Alexander’s ads.

Although Tennessee is not a border state, Carr cited up to a quarter of a million illegal immigrants living in the state, including 81,000 undocumented minors putting a burden on the state.

“It is a serious issue for Tennessee,” he said.

Carr points to tough reforms on illegal immigration that he personally worked on in the Tennessee House of Representatives. During his fights, Carr explained, he frequently found himself on the wrong side of the Republican establishment.

“It’s always the Republican leadership,” he said, pointing to the influence of the Chamber of Commerce and a series of big business lobbyists to help bring in more cheap labor.

He dismissed critics who suggest that Republicans lack compassion in the immigration reform debate.

“There’s nothing more compassionate than the law when it’s equally and fairly applied to everybody without regard to race, creed, color, or national origin,” he said.

In response to Carr’s attacks, Alexander has stiffly defended his support for the Senate immigration reform bill–one of fourteen Republicans who voted in favor of it.

“I voted to double border security, to end perpetual amnesty, and create a legal immigration system, and if anybody’s got a better idea, they should suggest it,” Alexander said. In response to the flood of unaccompanied minors crossing the border, last week Alexander called for the National Guard to be sent to the border.

But Ingraham and Carr spent their rally on Tuesday skewering Alexander’s support for the bill–much to the delight of the crowd, who are increasingly attentive to the issue.

In spite of his enthusiasm, Carr is facing some difficult hurdles in his campaign.

The state of Tennessee with a primary that has no runoff election, meaning that Alexander only has to earn a majority of the votes to win.

That might have saved Republicans like Chris McDaniel in Mississippi, who came up short in the election against Thad Cochran–only to lose in the runoff election. But in underdog elections, it can be an advantage, as demonstrated by Sen. Ted Cruz’s winning campaign against Texas Lieutenant Governor David Dewhurst.

Tennessee also has an open primary, meaning that any Democrat who wants to vote for Alexander can do so.

But Carr explains that if he loses, he’ll be comfortable with the verdict of the voters.

“We will not say that someone came in and cost us the race, we won’t do that, because that’s not the case,” he said. “If we fail we have no one to blame but ourselves.”